Sledgehammer already working on a new title?

SystemLink: "If you follow the Call of Duty series at all, you might recall the founding of Activision Blizzard's Sledgehammer Games studio. Tasked with the creation of a brand new Call of Duty game, Sledgehammer’s first foray into the field is said to be a departure from the standard FPS formula that made the series famous. While that game has yet to fully surface, it looks as though Sledgehammer may be hard at work on another, currently unannounced title."